Image pickup control apparatus, image pickup control method, image pickup control system, and storage medium

ABSTRACT

In an image pickup control apparatus capable of remotely and reliably controlling an image pickup apparatus from another apparatus, control data for controlling the image pickup apparatus is stored in advance and is transmitted to the image pickup apparatus when the image pickup apparatus is connected via data communications interface units.

CROSS-REFERENCE TO RELATED APPLICATION

This is a divisional application of application Ser. No. 09/348,500,filed Jul. 7, 1999 now U.S. Pat. No. 6,980,233.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to image pickup control techniquessuitable for controlling, from an external apparatus, an image pickupapparatus such as a video camera for electronically performing an imagepickup operation.

2. Related Background Art

Peripheral apparatuses of a personal computer (hereinafter abbreviatedas PC), such as a hard disk drive and a printer, are connected to PC viaa small computer general interface typically a SCSI (Small ComputerSystem Interface) of a digital interface (hereinafter described as adigital I/F). Data communication between PC and peripheral apparatusesis performed via the digital I/F.

Recently, cameras for electronically performing an image pickupoperation, such as digital cameras and digital video cameras, arepositively used as peripheral apparatuses for inputting an image to PC.Specifically, a still image or moving image taken with a digital cameraor video camera as well as associated sounds is entered to PC and storedin a hard disk, or edited and thereafter printed out by a color printer.Techniques in this field have been developed greatly and the number ofusers is increasing rapidly. With such techniques, when image dataentered from a camera into PC is output to a printer or hard disk, datacommunication is performed via SCSI or the like. In this case, sinceimage data having a large data amount is transferred, a digital I/F isrequired to have a high data transfer rate and be suitable for generaluse.

FIG. 33 shows a conventional system configuration of a digital cameraand a printer both connected to a PC. In FIG. 33, reference numeral 31represents a digital camera, reference numeral 32 represents a PC, andreference numeral 33 represents a printer. Reference numeral 34represents a memory serving as a storage unit of the digital camera 31,reference numeral 35 represents a decoding circuit for image data,reference numeral 36 represents an image processing unit, referencenumeral 37 represents a D/A converter, reference numeral 38 representsan EVF functioning as a display unit, and reference numeral 39represents a digital I/O unit for the digital camera 31. Referencenumeral 40 represents a digital I/O unit for PC 32 for the connection tothe digital camera 31, reference numeral 41 represents an operation unitsuch as a keyboard and a mouse, reference numeral 42 represents adecoding circuit for image data, reference numeral 43 represents adisplay, reference numeral 44 represents a hard disk drive, referencenumeral 45 represents a memory such as a RAM, reference numeral 46represents a MPU as a computation unit, reference numeral 47 representsa PCI bus, and reference numeral 48 represents a SCSI interface (board)as a digital I/F. Reference numeral 49 represents a SCSI interface ofthe printer 33 connected to PC 32 via a SCSI cable, reference numeral 50represents a memory, reference numeral 61 represents a printer head,reference numeral 52 represents a printer controller as a printercontrol unit, and reference numeral 53 represents a driver.

The following processes are executed in order to enter an image takenwith the digital camera into PC 32 and output the image from PC 32 tothe printer 33. Namely, in the digital camera, image data stored in thememory 34 and read therefrom is decoded by the decoding circuit 35,processed for image data display by the image processing circuit 36, anddisplayed on EVF 38 via the D/A converter 37. In order to output imagedata to PC 32, the image data is supplied to the digital I/O unit 40 ofPC 32 via the digital I/O unit 39.

In PC 32, the PCI bus 47 is used as an internal transfer bus. The imagedata input from the digital I/O unit 40 is either stored in a hard diskof the hard disk drive 44, or displayed on the display 43 after it isdecoded by the decoding circuit 42, stored in the memory 46 andconverted into analog signals in the display 43. When image data isedited by PC 32, necessary data is input via the operation unit 41. Thecontrol of the whole system of PC 32 is performed by MPU 46.

When an image is to be printed out, the image data is transferred fromPC 32 and via the SCSI interface unit 48 and SCSI cable to the SCSIinterface unit 49 of the printer 33, and converted into print image datain the memory 50. The printer controller 52 controls the printer head 61and driver 53 to print out the print image data in the memory 50.

As above, each peripheral apparatus is connected to PC which functionsas a host, and image data picked up with a camera is printed out via PC.However, SCSI is associated with several problems including a lowtransfer data rate, a thick parallel communications cable, restrictionson the type of a connectable peripheral apparatus and on the connectionmethod, and a necessity of I/F connectors same in number as the numberof connection destinations.

Most of general home use PCes and digital apparatuses have connectorsfor connection to SCSI and cables on the back panel thereof. The size ofsuch a connector is large and a work of inserting and removing theconnector is cumbersome. Even a mobile or portable apparatuses which arenot used as a mount-type, such as a digital camera and a video camera,is required to be connected to the connector on the back panel of PC anda user feels very cumbersome.

Digital data communications have been heretofore typically mutualcommunications between PC and its peripheral apparatus, and conventionalcommunications systems are not so much inconvenient. However, it isexpected that the number of types of apparatuses handling with digitaldata increases, and that not only PC peripheral apparatuses, but alsoother digital apparatuses such as digital video apparatuses and digitalrecording medium reproducing apparatuses can be connected to a networkwith the advent of improved I/F to realize network communications.Although network communications are very convenient, communications witha large data amount are performed often between some apparatuses. Insuch a case, the network traffics become congested and communicationsbetween other apparatuses in the network may be affected adversely, if aconventional communication method is used.

Digital I/F for general use (such as high performance serial bus IEEE1394-1995 (The Institute of Electrical and Electronics Engineers)) hasbeen proposed which is applicable to communications not only between PCand its peripheral apparatuses but also between digital apparatuses ofvarious types and can solve problems of conventional digital I/F as muchas possible. By using such digital I/F for general use, PCes, theirperipheral apparatuses such as printers, digital cameras, digital VTRswith built-in camera, and the like are connected together to configure anetwork and realize data communications between these apparatuses.

Main characteristics of IEEE 1394 reside in that, as will be laterdetailed, its cable is relatively thin and rich in flexibility and itsconnector is very small as compared to a SCSI cable because of highspeed serial communications, and that data having a large capacity suchas image data can be transferred together with apparatus-control data athigh speed. With communications using IEEE 1394 I/F, even a portableapparatus which is not usually used as a mount-type, such as a digitalcamera and a video camera, can be connected easily with a considerablyreduced conventional cumbersome work, and image data ca be transferredto PC smoothly.

As above, IEEE 1394 I/F has various advantages which overcome cumbersomeworks associated with a conventional data communications system. Datahaving a large capacity, particularly image data, can be transferredtogether with apparatus control data at high speed. It is thereforepossible, for example, for PC to perform a remote real time control ofan image pickup apparatus typically a video camera in accordance withimage data transferred from the image pickup apparatus. There istherefore a high possibility to realize the conventional issue ofremotely and reliably controlling an image pickup from anotherapparatus.

SUMMARY OF THE INVENTION

The present invention has been made under the above-described backgroundand it is an object of the present invention to remotely and reliablycontrol an image pickup apparatus from another apparatus.

In order to solve the above object, according to one aspect of thepresent invention, there is provided an image pickup control apparatusfor controlling an image pickup apparatus via a data communicationsinterface unit, comprising: storage means for storing control data forcontrolling the image pickup apparatus; connection detecting means fordetecting a connection to the image pickup apparatus via the datacommunications interface unit; and transmission control means fortransmitting the control data stored in the storage means to the imagepickup apparatus when the connection detecting means detects aconnection to the image pickup apparatus.

According to another aspect of the invention, there is provided an imagepickup control method for controlling an image pickup apparatus via adata communications interface unit, comprising: a storage step ofstoring control data for controlling the image pickup apparatus; aconnection detecting step of detecting a connection to the image pickupapparatus via the data communications interface unit; and a transmissioncontrol step of transmitting the control data stored at the storage stepto the image pickup apparatus when the connection detecting step detectsa connection to the image pickup apparatus.

According to another aspect of the invention, there is provided an imagepickup control system for controlling an image pickup apparatus via adata communications interface unit, comprising: storage means forstoring control data for controlling the image pickup apparatus;connection detecting means for detecting a connection to the imagepickup apparatus via the data communications interface unit; andtransmission control means for transmitting the control data stored inthe storage means to the image pickup apparatus when the connectiondetecting means detects a connection to the image pickup apparatus.

According to another aspect of the invention, there is provided astorage medium storing a control program for controlling an image pickupapparatus via a data communications interface unit, wherein the programcomprises: a storage routine of storing control data for controlling theimage pickup apparatus; a connection-detecting routine of detecting aconnection to the image pickup apparatus via the data communicationsinterface unit; and a transmission control routine of transmitting thecontrol data stored at the storage routine to the image pickup apparatuswhen the connection detecting routine detects a connection to the imagepickup apparatus.

According to another aspect of the invention, there is provided an imagepickup control apparatus for controlling an image pickup apparatus via adata communications interface unit, comprising: storage means forstoring a plurality set of control data corresponding to a plurality ofphotographing modes, the control data controlling the image pickupapparatus; connection detecting means for detecting a connection of theimage pickup apparatus via the data communication interface unit; andtransmission control means for transmitting the control data stored inthe storage means to the image pickup apparatus when a connection to theimage pickup apparatus is detected by the connection detecting means andif it is judged that the image pickup apparatus is in a controllablestate.

The storage means, process and routine may store the control data forcontrolling a stop, a hue, a color density and a shutter speed.

The image pickup control apparatus, method, system and storage mediummay further comprise reception detecting means, process and routine fordetecting a control reception state of the image pickup apparatus,wherein the transmission control means, process and routine transmit thecontrol data stored in and at the storage means, process and routine tothe image pickup apparatus when the connection detecting means, processand routine detect a connection to the image pickup apparatus and whenthe reception detecting means, process and routine detect a controlreception state of the image pickup apparatus.

The image pickup apparatus, method, system and storage medium may havestorage means, process and routine for storing the control datatransmitted from and at the transmission control means, process androutine as current control data.

The storage means, process and routine may store the control data foreach of a plurality of photographing conditions, and the image pickupcontrol apparatus, method, system and storage medium may furthercomprise guide means, process and routine for guiding to select adesired photographing condition by displaying a plurality ofphotographing conditions stored in and at the storage means, process androutine and the transmission control means, process and routine transmitthe control data corresponding to the desired photographing conditionselected by being guided by and at the guide means, process and routine.

The photographing condition may be based upon an environment andphotographing state of a subject, the environment and photographingstate including evening photographing, wedding reception photographing,closeup photographing, ski ground photographing, night scenephotographing and other photographing.

The image pickup control apparatus, method, system and storage mediummay further comprise display control means, process and routine fordisplaying a model image corresponding to the control data for thedesired photographing condition selected by being guided by the guidemeans, process and routine.

The image pickup control apparatus, method, system and storage mediummay further comprise change means, process and routine for changing thecontrol data corresponding to the model image by referring to the modelimage displayed by the display control means, process and routine,wherein the transmission control means, process and routine transmit thecontrol data changed by the change means, process and routine to theimage pickup apparatus.

The display control means, process and routine may display the modelimage corresponding to the control data changed by the change means,process and routine.

The image pickup control apparatus, method, system and storage mediummay further comprise rewrite means, process and routine for changing thecontrol data stored in and at the storage means, process and routine tothe control data changed by the change means, process and routine.

The image pickup control apparatus, method, system and storage mediummay further comprise return instruction means, process and routine fortransmitting the control data corresponding to the desired photographingcondition selected by being guided by the guide means, process androutine and instructing the image pickup apparatus to return aphotographed image corresponding to the control data.

The display control means, process and routine may display thephotographed image returned from the image pickup apparatus in responseto an instruction by the return instruction means, process and routine.

The change means, process and routine may change the control datacorresponding to the photographed image by referring to the photographedimage displayed by the display control means, process and routine, andthe transmission control means, process and routine transmit the controldata changed by the change means, process and routine to the imagepickup apparatus.

The return instruction means, process and routine may transmit thecontrol data changed by the change means, process and routine andtransmitted by the transmission control means, process and routine tothe image pickup apparatus and instruct the image pickup apparatus toreturn the photographed image corresponding to the changed control data.

According to another aspect of the invention, there is provided an imagepickup control apparatus, method, system and storage mediums for asystem in which an image pickup apparatus and a printer are connectedvia data communications interface units, comprising: detecting means,process and routine for detecting a print performance of the printerwhen a detection between the image pickup apparatus and the printer isdetected; and transmission control means, process and routine fortransmitting a photographed image from the image pickup apparatus to theprinter, the photographed image having a definition corresponding to theprinter performance detected by the detecting means, process androutine.

The data communications interface unit may comprise a general digitalinterface unit.

The data communications interface unit may conform with an IEEE 1394interface bus.

The storage means may store the control data corresponding to thephotographing mode for controlling a stop, a hue, a color density and ashutter speed.

The image pickup control apparatus, method, system and storage mediummay further comprise control means for controlling to allow the controldata to control the image pickup apparatus when the image pickupapparatus is in a manual setting mode, wherein the transmission controlmeans transmits the control data stored in the storage means to theimage pickup apparatus when the connection detecting means detects aconnection to the image pickup apparatus and when the image pickupapparatus is controllable.

The photographing mode may be based upon an environment andphotographing state of a subject, the environment and photographingstate including evening photographing, wedding reception photographing,closeup photographing, ski ground photographing, night scenephotographing and other photographing.

The control means may further comprise display control means fordisplaying a model image corresponding to the control data for aselected photographing mode, when the control data is set in accordancewith the photographing mode.

The image pickup control apparatus, method, system and storage mediummay further comprise change means for changing the control datacorresponding to the model image by referring to the model imagedisplayed by the display control means, wherein the transmission controlmeans transmits the control data changed by the change means to theimage pickup apparatus.

The display control means may display a model image corresponding to thecontrol data changed by the change means.

The above, and other objects, features and advantages of the presentinvention will be apparent from the following detailed description ofillustrative embodiments which is to be read in connection with theaccompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic diagram showing an example of the configuration ofa network of an IEEE 1394 communications system.

FIG. 2 is a diagram showing an example of connections betweenapparatuses using IEEE 1394 serial buses.

FIG. 3 is a block diagram showing constituent elements of an IEEE 1394serial bus.

FIG. 4 is a diagram showing an address space of an IEEE 1394 serial bus.

FIG. 5 is a cross sectional view of an IEEE 1394 serial bus cable.

FIG. 6 is a timing chart illustrating a DS-Link coding method using adata transfer format of an IEEE 1394 serial bus.

FIG. 7 is a flow chart illustrating the outline of processes from a busreset to a node ID determination.

FIG. 8 is a flow chart illustrating the details of processes from thebus reset to a root determination shown in FIG. 7.

FIG. 9 is a flow chart illustrating the details of processes after theroot determination to an ID setting shown in FIG. 7.

FIG. 10 is a flow chart illustrating processes to be followed by theflow chart shown in FIG. 9.

FIG. 11 is a diagram illustrating a specific example of determining aparent/child relation when node IDes are determined.

FIGS. 12A and 12B are diagrams illustrating a bus use request and a bususe permission.

FIG. 13 is a flow chart illustrating an arbitration process for a bususe right.

FIG. 14 is a diagram showing a time sequential transition state of anasynchronous transfer.

FIG. 15 is a diagram showing an example of a packet format of theasynchronous transfer.

FIG. 16 is a diagram showing a time sequential transition state of anisochronous transfer.

FIG. 17 is a diagram showing an example of a packet format of theisochronous transfer.

FIG. 18 is a diagram showing a time sequential transition state of acombination of the isochronous transfer and asynchronous transfer.

FIG. 19 is block diagram of an information transfer path including IEEE1394 I/F units.

FIG. 20 is a block diagram showing the outline structure of a videocamera according to an embodiment of the invention.

FIG. 21 is a flow chart illustrating processes up to a start of a modesetting program execution by PC shown in FIG. 20.

FIG. 22 is a flow chart illustrating processes up to a mode settingoperation for the video camera shown in FIG. 20.

FIG. 23 is a flow chart illustrating the outline of a mode settingprogram.

FIG. 24 is a diagram showing a mode selection menu screen.

FIG. 25 is a diagram showing a PC screen when an evening sunphotographing mode is selected.

FIG. 26 is a diagram showing types of camera control commands.

FIG. 27 is a flow chart illustrating processes to be executed in aphotographing condition setting mode.

FIG. 28 is a diagram showing a PC screen when an evening sunphotographing condition setting mode is executed.

FIG. 29 is a flow chart illustrating a photographing condition settingprocess.

FIG. 30 is a flow chart illustrating processes to be executed in aphotographing image confirming and condition setting mode.

FIG. 31 is a diagram showing a PC screen during the photographing imageconfirming and condition setting mode.

FIG. 32 is a diagram showing a PC screen when a camera is set during thephotographing image confirming and condition setting mode.

FIG. 33 is a diagram showing an example of a conventional datacommunications system using SCSi.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Preferred embodiments of the invention will be described with referenceto the accompanying drawings.

FIG. 1 is a diagram showing the system environment incorporating animage pickup apparatus of this invention. Under this system environment,the apparatuses are connected by serial bus cables C (hereinafter called1394 bus cables) of IEEE 1394.

In FIG. 1, reference numeral 101 represents a TV monitor, and referencenumeral 102 represents an AV amplifier connected to the TV monitor 101via a 1394 bus cable C. The AV amplifier 102 selects a particularapparatus from various apparatuses connected by 1394 bus cables C, andtransfers audio visual data from the selected apparatus to the TVmonitor 101.

Reference numeral 103 represents a PC connected to the AV amplifier 102via a 1394 bus cable C, and reference numeral 104 represents a printerconnected to PC 103 via a 1394 bus cable C. PC 103 can receive an imagefrom any of various apparatuses via 1394 bus cables C and print it outat the printer 104.

Reference numeral 105 represents a first digital VTR connected to theprinter 1394 via a 1394 bus cable C, reference numeral 106 represents asecond digital VTR connected to the first digital VTR via a 1394 buscable C, reference numeral 107 represents a DVD player connected to thesecond digital VTR 106 via a 1394 bus cable C, and reference numeral 108represents a CD player connected to the DVD player 107 via a 1394 buscable C.

The network shown in FIG. 1 is only illustrative, and other apparatusesmay be connected at the downstream of the TV monitor 101 and CD player108. External storage devices such as hard disks, a second CD player, asecond DVD player may also be connected by 1394 bus cables C.

In this embodiment, as digital I/F for connecting apparatuses, an IEEE1394 serial bus is used. The details of the IEEE 1394 serial bus will begiven first.

Outline of IEEE 1394 Technologies

With the advent of home digital VTR and DVD, it is becoming highlynecessary to transfer in real time a great amount of data such as videoand audio data. In order to transfer in real time video and audio datato PC or other digital apparatuses, an interface capable of high speeddata transfer is necessary. An interface developed from this viewpointis IEEE 1394-1995 (high performance serial bus: 1394 serial bus).

FIG. 2 shows an example of a network system using 1394 serial buses.This system has apparatuses A, B, C, D, E, F, G and H. Twist pair cablesof the 1394 serial bus are connected between the apparatuses A and B, Aand C, B and D, D and E, C and F, C and G, and C and H. Theseapparatuses A to H may be a PC, a digital VTR, a DVD, a digital camera,a hard disk, a monitor and the like.

A connection method for the apparatuses enables a mixture of a daisychain method and a node branch method, which provides a high degree ofconnection freedom. Each apparatus has an ID specific thereto. Onenetwork is configured within the area connected by 1394 serial buses,while each apparatus confirms a partner ID. By sequentially connectingthe digital apparatuses with 1394 serial buses, each apparatus canfunction as a relay apparatus to constitute one network. A Plug & Playfunction characteristic to the 1394 serial bus automatically recognizesan apparatus and its connection state when the cable is connected to theapparatus.

In the system shown in FIG. 2, when an apparatus is disconnected from ornewly added to the network, a bus reset is automatically performed toreset the network configuration and reconfigure a new network. Thisfunction allows to always set and recognize the configuration of anetwork at that time.

Three data transfer speeds are provided including 100 Mbps, 200 Mbps,and 400 Mbps. An apparatus having a higher transfer speed supports anapparatus having a lower transfer speed to establish compatibilitytherebetween. Data transfer modes include an asynchronous transfer modefor transferring asynchronous data (Async data) such as a control signaland an isochronous transfer mode for transferring isochronous data (Isodata) such as real time video and audio data. The Async data and Isodata are transferred in a mixed state during each cycle (usually onecycle is 125 μs) after a cycle start packet (CSP) indicating a cyclestart is transferred, with the Iso data transfer being given a priorityover the Async data transfer.

FIG. 3 shows the constituent elements of the 1394 serial bus. As shown,the 1394 serial bus has as a whole a layer (hierarchical) structure. The1394 serial bus cable C is most like hardware. At the upper level of aconnector port to which the cable C is connected, there is a hardwaresection of a physical layer and a link layer. This hardware section issubstantially made of an interface chip. Of the hardware section, thephysical layer performs coding, connector related control and the like,while the link layer performs packet transfer, cycle time control andthe like.

A transaction layer in a firmware section manages data to be transferred(transacted) and issues a read/write command. A serial bus management ina firmware section manages the configuration of the network, such as aconnection state and ID of each connected apparatus. The hardware andfirmware sections constitute a substantial 1394 serial bus. Anapplication layer in a software section changes with software to beused, and defines how data is placed on the interface, in accordancewith a protocol such as an AV protocol.

FIG. 4 shows an address space of the 1394 serial bus. It is essentialthat each apparatus (node) connected to the 1394 serial bus has anaddress of 64 bits specific to the node. This address is stored in a ROMso that the addressees of each node and a partner node can be recognizedalways and communications with a designated partner can be performed.Addressing of the 1394 serial bus is in conformity with IEEE 1212. Ofthe 64-bit address space, the first 10 bits are used for designating thebus number, and the next 6 bits are used for designating the node ID.The remaining 48 bits are used as an address width assigned to theapparatus. Of these specific address space, the last 28-bit addressspace is used as a specific data area in which an identification code ofthe apparatus, use condition designation information, and the like arestored.

Technologies characteristic to the 1394 serial bus will be described inmore detail.

Electrical Specifications of 1394 Serial Bus

FIG. 5 is a cross sectional view of a 1394 serial bus cable C. With the1394 serial bus, a connection cable accommodates two pairs of twistedsignal conductors as well as electric power supply conductors. A powercan therefore be supplied to an apparatus without a power supply, anapparatus with a voltage lowered by accidents, and other apparatuses. Asimple connection cable has no electric power supply conductor and islimited to a connection of a particular apparatus. A voltage at theelectric power supply conductors is stipulated to be 8 to 40 V and acurrent is stipulated to be 1.5 A DC at the maximum.

DS-Link Coding

The DS-Link coding method for data transfer adopted by the 1394 serialbus will be described with reference to FIG. 6. The 1394 serial busadopts the DS-Link (Data/Strobe Link) coding method. This DS-Link codingmethod is suitable for high speed serial data communications andrequires two pairs of twisted signal conductors. Main data istransferred via one pair of twisted conductors and a strobe signal istransferred via the other pair of twisted conductors. On the receptionside, a clock signal can be reproduced through exclusive logical OR ofthe reception data and strobe signal.

The merits of using the DS-Link coding method are, for example, that thetransfer efficiency is higher than other serial data transfer methods,that a circuit scale of a controller LSI can be made small because a PLLcircuit is not necessary, and that since information representative ofan idle state is not necessary when there is no data to be transferred,a transceiver circuit of each apparatus can be set to a sleep state andthe consumption power can be lowered.

Sequence of Bus Reset

With the 1394 serial bus, each connected apparatus (node) is given anode ID so that each apparatus can be recognized as a constituent memberof the network. If the network configuration changes, for example, ifthe number of nodes increases or decreases because of a node insertionor disconnection or power on/off, the new network configuration isrecognized. In this case, the node which detected such a changetransmits a bus reset signal to the bus to enter a mode of recognizingthe new network configuration. A change can be detected by monitoring achange in the bias voltage at the board of the 1394 IF port.

After a bus reset signal is transmitted from one node and when thephysical layer of another node receives it, the physical layer notifiesa reception of the bus reset signal to the link layer and transmits thebus reset signal to another node. After all the nodes detect the busreset signal, a bus reset process is activated. The bus reset process isactivated not only through hardware detection such as cable insertionand disconnection and network abnormality but also through a commandissued directly to the physical layer under the host control by aprotocol. When the bus reset process is once activated, the datatransfer is temporarily suspended, and after the bus reset process iscompleted, the data transfer resumes under the new networkconfiguration.

Sequence of Node ID Determination

After completion of the bus reset process, each node is assigned a newID in order to reconfigure the new network. The general sequence fromthe bus reset to node ID determination will be described with referenceto the flow charts of FIGS. 7 to 10.

The flow chart shown in FIG. 7 illustrates a series of processes to beexecuted by the bus, from a bus reset occurrence to a node IDdetermination and a data transfer resumption. First at Step S101, anoccurrence of a bus reset in the network is always monitored, and when abus reset occurs because of a node power on/off or the like, the flowadvances to Step S102. At Step S102 each node connected to the networkdeclares a parent/child relation in order to know the new networkconnection state from the network reset state.

When the parent/child relation is determined for all nodes (Step S103),one node is determined which can function as a root node for all othernodes. Until the parent/child relation is determined for all nodes, theroot node cannot be determined. After the root node is determined atStep S104, a node ID setting work is performed at Step S105 to assigneach node a node ID. This node ID setting work is repetitively performed(Step S106) until all the nodes are assigned ID in the order ofleaf→node branch node→leaf node to be described later. After all thenodes are assigned ID, the new network configuration can be recognizedby all the nodes. Therefore, at Step S107 a data transfer betweendesired nodes is made possible and if necessary the data transfer isperformed. In this state of Step S107, a mode of monitoring anoccurrence of the bus reset starts again, and if the bus reset isdetected, the setting work from Step S101 to Step S106 is repeated.

The details of the process from the bus reset to the root determinationand the process after the root determination to the ID setting,illustrated in the flow chart of FIG. 7, will be given with reference tothe flow charts of FIGS. 8 to 10.

First, the procedure from the bus reset to the root node determinationwill be described with reference to the flow chart of FIG. 8. When anoccurrence of a bus reset is detected at Step S201, the flow advances toStep S202 whereat a flag indicating a leaf node is set at eachapparatus, as a first step of a work for reconfirming the connectionstate of the reset network. Next, at Step S203 the number of other nodesconnected to a port or ports of each node is checked.

The number of undefined ports (whose parent/child relation is still notdetermined) is checked (Step S204) in order to start the declaration ofa parent/child relation in accordance with the check result of thenumber of connected ports. Although the number of ports is equal to thenumber of undefined ports immediately after the bus reset, the number ofundefined ports checked at Step S204 changes as the parent/childrelation is determined. Only a leaf node can declare the parent/childrelation immediately after the bus reset. The node is judged as a leafnode if the number of undefined ports checked at Step S204 is “1”.

If the node is a leaf node, at Step S205 a declaration that “this nodeis a child and the partner is a parent” is made to the node connected tothe leaf node, to thereafter terminate the process. If a node isrecognized as a branch node because of a plurality of connected ports atStep S203 and a plurality of undefined ports at Step S204 immediatelyafter the bus reset, a flag indicating a branch is set at Step S206, andat Step S207 the routine stands by to receive “parent” of theparent/child relation declaration from the leaf node. The branch nodereceived the parent/child relation declaration from the leaf node atStep S207, checks again the number of undefined ports at Step S204. Ifthe number of undefined ports is “1” a declaration that “this node is achild” is issued to the node connected to the remaining port at StepS205.

If the branch node has two or more undefined nodes even at the second orlater check at Step S204, the routine again stands by at Step S207 toreceive “parent” from a leaf node or branch node. If the number ofundefined ports checked at Step S204 becomes “0” at any branch node or aleaf node (in an unusual case of not quickly issuing a childdeclaration), it means that the parent/child declaration of the wholenetwork was completed. A flag indicating a root is set at Step S208 forthis single node having no undefined port (all ports determined asparent), and the node is confirmed as the root node at Step S209.

Next, the details of the process after the root node determination tothe ID setting completion will be described with reference to the flowcharts of FIGS. 9 and 10.

In accordance with the flag information for the leaf, branch and rootdetermined by the sequence shown in FIG. 8, the nodes are classifiedinto the leaf nodes, branch nodes and root node at Step S301. In thework of assigning each node an ID, a leaf node can be assigned ID at thefirst. IDes from a smaller number (starting from a node number=0) areset in the order of leaf node→branch node→root node.

In the case of the leaf node, the number N (natural number) of leafnodes in the network is set at Step S302. Thereafter, at Step S303 eachleaf node requests ID from the root node. Upon reception of the requestsfrom a plurality of leaf nodes, the root node performs arbitration (toselect one leaf node) at Step S304. At Step S305 one victory node isassigned an ID number and remaining defect nodes are notified of afailure.

Each leaf node checks at Step S306 whether ID was acquired. If not, theflow returns to Step S303 whereat an ID request is again issued torepeat the above operations. If ID is acquired, at Step S307 a self-IDpacket is broadcast to all nodes. This self-ID packet containsinformation such as a node ID, the number of ports of the node, thenumber of already connected ports, whether each port is a parent orchild, and whether the node has an ability of a bus manager (if the nodehas a bus manager ability, a contender bit in the self-ID packet is setto “1”, whereas if not, it is set to “0”).

The bus manager ability allows the following bus managements:

(1) Bus power supply management: Management of whether each apparatus ofthe network shown in FIG. 1 is an apparatus which requires a powersupply via the electric power supply conductors in the connection cableor an apparatus which has its own power supply.

(2) Maintenance of a speed map: Maintenance of communications speedinformation of each apparatus of the network.

(3) Maintenance of a network configuration (topology map): Maintenanceof tree structure information such as shown in FIG. 11.

(4) Bus optimization based upon information acquired from the topologymap.

The bus manager node performs a bus management of the whole network byusing the procedure to be later described. The node having the abilityof a bus manager, i.e., the node which broadcasts the self-ID packethaving the contender bit of “1”, stores information such as acommunications speed in the self-ID packets broadcast from the othernodes. When the node becomes the bus manager, it forms the speed map andtopology map in accordance with the stored information.

After the node-ID packet is broadcast, the number of remaining leafnodes is decremented by “1” at Step S308. If it is judged at Step S309that the number of remaining leaf nodes still not acquiring ID is “1” orlarger, the flow returns to Step S303 to repeat the above operation. Ifthe count N is “0”, i.e., if the number of remaining leaf nodes stillnot acquiring ID is “0” and all the leaf nodes acquired ID and broadcastthe self-ID packet, then the ID setting for branch nodes starts.

The ID setting for branch nodes is similar to the leaf nodes. First atStep S310 the number M (natural number) of branch nodes in the networkis set. Thereafter, at Step S311 each branch node requests ID from theroot node. In response to this, the root node performs arbitration atStep S312. Each victory node is assigned ID starting from the smallernumber next to the last number assigned to the leaf node. At Step S313,the root node assigns ID to the branch node issued the ID request ornotifies the branch node of a arbitration failure.

Each branch node issued the ID request checks at Step S314 whether IDwas acquired. If not, the flow returns to Step S311 whereat an IDrequest is again issued to repeat the above operation. If ID isacquired, at Step S315 a self-ID packet is broadcast to all other nodes.After the self-ID packet of one branch node is broadcast, the number ofremaining branch nodes is decremented by “1” at Step S316. If it isjudged at Step S317 that the number of remaining branch nodes still notacquiring ID is “1” or larger, the flow returns to Step S311 to repeatthe above operation.

If the count M is “0”, i.e., if the number of remaining branch nodesstill not acquiring ID is “0” and all the branch nodes acquired ID andbroadcast the self-ID packet, it means that the node still not acquiringID is only the root node. In this case, at Step S318 the ID numberhaving the largest number still not assigned is set to the root nodeitself. At Step S319, a self-ID packet of the root node is broadcast.

With the above processes, a presence/absence of the bus manager abilityof each node becomes clear. If a plurality of nodes have the bus managerability, the node having the largest ID number becomes the bus manager.If the root node has the bus manager ability, it becomes the bus managerbecause it has the largest ID number in the network, whereas if the rootnode does not have the bus manager ability, the branch node having thelargest ID number next to the root node and having the contender bit of“1” in the self-ID packet becomes the bus manager.

Which node is the bus manager can be recognized by each node by storingbroadcasting information as to the information of the ID packets of allother nodes broadcast when the ID was acquired in the processing shownin FIGS. 9 and 10.

The above operations will be described more specifically by taking as anexample the network shown in FIG. 11. In the network shown in FIG. 11,nodes A and C are directly connected to a root node B at its lowerlevel. A node D is directly connected to the node C at its lower level.Nodes E and F are directly connected to the node D at its lower level.In this manner, a hierarchical structure of the network is formed.

The procedure of determining such a hierarchical structure, rood nodeand node IDes is as in the following. After a bus reset is detected, aparent/child relation declaration is made between ports directlyconnecting respective nodes, in order to confirm the connection state ofrespective nodes. A parent is at a higher level of the hierarchicalstructure, and a child is at a lower level. In the example shown in FIG.11, after a bus reset is detected, the node A issues the parent/childrelation declaration at the first time. Basically, the node having aconnection at only one port, i.e., a leaf node, can issue theparent/child relation declaration at the first time. This is because aconnection at only one port can be confirmed easily. A parent/childrelation is determined starting from one of leaf nodes which confirmedthat the node is at the end of the network and which operated first.

The port on the node side which made the parent/child relationdeclaration (node A between nodes A and B) is determined as a child, andthe port on the partner side (node B) is determined as a parent. In thismanner, child and parent are set to the nodes A and B, child and parentare set to the nodes E and D, and child and parent are set to the node Fand D. At the level higher by one level, of the branch nodes having aplurality of connection ports, the parent/child relation declaration ata next higher level is made sequentially starting from the branch nodereceived the parent/child relation declaration from other nodes. In theexample shown in FIG. 11, after the parent/child relations between thenodes D and E and between the nodes D and F are determined, the node Dissues a parent/child relation declaration to the associated branch nodeC so that child and parent are set to the nodes D and C. The branch nodeC received the parent/child relation declaration from the node D issuesa parent/child relation declaration to the node B connected to the otherport so that child and parent are set to the nodes C and B.

In the above manner, the hierarchical structure shown in FIG. 11 isformed. The node B as a parent for all the other connected nodes becomesthe root node. There is only one root node in one network. In theexample shown in FIG. 11, although the node B is determined as the rootnode, the root node may be another node if the node B received theparent/child relation declaration from the node A issues a parent/childrelation declaration to the other node at the earlier timing. Namely,depending upon the timing of issuing a declaration, any node has apossibility of becoming the root node, and the root node is notdetermined unanimously even in the same network configuration.

After the root node is determined, a mode of determining each ID enters.All nodes notify the determined node IDes to other nodes (broadcastfunction). Self-ID information contains information such as the nodenumber, the connection position, the number of ports, the number ofconnected ports, and the parent/child relation of each port.

As the procedure of distributing node ID numbers, the leaf node having aconnection at only one port can activate the ID determination operation.The nodes numbers 0. 1. 2, . . . are sequentially assigned in theactivation order. The node acquired the node ID broadcasts theinformation including the node number to other nodes. Therefore, each ofthe other nodes can recognize that the ID number was “already assigned”.After all the leaf nodes acquire their IDes, branch nodes acquire IDes.The node IDes following the largest ID number assigned to the leaf nodeare assigned to branch nodes. Similar to the leaf node, the branch nodebroadcasts the node ID, sequentially starting from the branch nodeassigned the node ID number. Lastly, the root node acquires its ID andbroadcasts the ID information. The root node has the largest node IDnumber in the network.

Arbitration

With the 1394 serial bus, prior to data transfer, arbitration for bususe right is essentially performed. The 1394 serial bus configures alogical bus type network in which each apparatus in the network relays atransferred signal to transfer it to all apparatuses (nodes) in thenetwork. Arbitration is therefore necessary in order to avoid packetcollision. Only one node can be permitted to transfer data during someperiod through arbitration.

The arbitration operation will be described with reference to FIGS. 12Aand 12B. FIG. 12A shows an example of a bus use request. As arbitrationstarts, one or a plurality of nodes request a bus use right to theparent node. In the example shown in FIG. 12A, nodes C and F request thebus use right. Upon reception of this request, the parent node (node Ain FIG. 12A) further requests (relays) the bus user right to the parentnode. This request is eventually received by the root node whichperforms a final arbitration. The root node received the requests forthe bus use right determines the node which can use the bus.

This arbitration operation is performed only by the root node. Thevictory node of arbitration is given the bus use right. In the exampleshown in FIG. 12B, the node C is permitted to use the bus, and the nodeF is refused to use the bus. As shown in FIG. 12B, a DP (Data Prefix)packet is transmitted to the arbitration defeat nodes to notify them ofa rejection of the bus use request. The bus use request at the rejectednode is suspended until the next arbitration. In this manner, thearbitration victory node permitted to use the bus can start datatransfer thereafter.

A series of arbitration operations will be descried with reference tothe flow chart shown in FIG. 13. The idle state of the bus becomesnecessary in order for the node to start data transfer. In order toconfirm whether the bus is presently idle after the completion ofprevious data transfer, each node judges that data transfer is possible,if a gap length (e.g., subaction gap) of a predetermined idle timeindependently preset for each transfer mode lapses.

At Step S401 it is judged whether a predetermined gap length preset foreach transfer data type such as Async data and Iso data is obtained, inorder to check whether the bus is presently in the idle state. Unlessthe predetermined gap length is obtained, a bus use right permitting thestart of data transfer cannot be requested so that the arbitrationoperation stands by until the predetermined gap length is obtained. Ifthe predetermined gap length is obtained at Step S401, it is judged atStep S402 whether there is data to be transferred. If not, the operationstands by, whereas if there is transfer data, the flow advances to StepS403 whereat a bus use right is requested to the root node to reservethe bus. A signal representative of the bus use right request is relayedby each apparatus of the network as shown in FIG. 12A and eventuallyreceived by the root node at Step S404.

Next, when the root node receives at least one bus use right request atStep S404, at Step S405 the root node checks the number of nodes fromwhich the bus use right request was issued at Step S403. If the numberof nodes is “1”, the node is permitted to use the bus immediatelythereafter (Step S408).

If there is a plurality of use right requested nodes, the root nodeperforms at Step S406, an arbitration for determining one node which ispermitted to use the bus. This arbitration is performed fairly and a usepermission is given equally to nodes without giving it to the same nodeat each arbitration. Of the plurality of use requested nodes, one nodeis given the use permission through arbitration by the root node at StepS407 and a bus use permission signal is transmitted to this node at StepS408. The node received this permission signal starts transferring data(packet) immediately after the predetermined gap length having a presetidle time.

To the other use requested nodes not given the use permission at StepS407, a DP (Data Prefix) packet indicating an arbitration failure istransmitted at Step S409. Upon reception of this packet, the flowreturns to Step S401 and stands by until the predetermined gap length isobtained in order to again issue a bus use request.

Asynchronous Transfer

Asynchronous transfer transfers data asynchronously. A time sequentialtransition state is shown in FIG. 14. In FIG. 14, the first subactiongap indicates a bus idle time. After this idle time continues apredetermined period, each node wishing to transfer data judges that thebus can be used and requests for arbitration to acquire the bus. When abus use permission is obtained through arbitration, the data istransferred in the form of packet. The node receiving the transfer datareturns a reception confirmation of the transfer data by transmittingeither an ack signal (reception confirmation response code) or aresponse packet after a short ack gap. The ack signal is constituted offour-bit information and four-bit check sum. The four-bit informationcontains information indicating a reception success, a busy state, or apending state.

FIG. 15 shows an example of a packet format used by asynchronoustransfer. A packet for asynchronous transfer includes a data field, anerror correction data CRC field and a header field. As shown in FIG. 15,the header field stores therein an object node ID, a source node ID, atransfer data length, various codes and the like. Asynchronous transferis one-to-one communications between each node and a partner node. Anasynchronous transfer packet transferred from a transfer source node isdistributed to respective nodes on the network. However, a packetdestined to other nodes different from the object node is neglected sothat only the node destined to the object node can be read.

Isochronous Transfer

Isochronous transfer transfers data isochronously. The isochronoustransfer which may be called the most characteristic feature of the 1394serial bus, is particularly suitable for a mode necessary for real timetransfer of data such as multimedia data including video data and audiodata. The asynchronous transfer is one-to-one data transfer, whereas theisochronous transfer provides a broadcast function of transferring datafrom one node to all other nodes equally.

FIG. 16 is a diagram showing a time sequential transition state ofisochronous transfer. The isochronous transfer is performed at apredetermined time interval on the bus. This time interval is called anisochronous cycle which is 125 μs. A cycle start packet indicates astart time of each cycle and has a roll of adjusting time at each node.The cycle start packet is transmitted from a node called a cycle master.The cycle start packet indicating the start of each cycle is transmittedafter a lapse of a predetermined idle time (subaction gap) after thecompletion of data transfer during the period one cycle before. Thiscycle start packet is transmitted at an time interval of 125 μs.

A plurality type of packets with channel IDes of channel A, channel Band channel C shown in FIG. 16 can be discriminately transmitted duringone cycle. Therefore, real time data transfer between a plurality ofnodes can be performed during one cycle. The reception node can receivethe data having only a desired channel ID. The channel ID is not adestination address but it is only a theoretical number of data.Therefore, each packet is broadcast from one source node to all othernodes.

Prior to transmission of an isochronous packet, arbitration is performedsimilar to the asynchronous transfer. However, since the isochronoustransfer is not one-to-one communications like the asynchronoustransfer, the isochronous transfer does not use the ack signal(reception confirmation response code). An iso gap (isochronous gap)shown in FIG. 16 corresponds to an idle period necessary for confirminga bus idle state prior to performing isochronous transfer. After thisidle period, a node wishing to perform isochronous transfer judges thatthe bus is idle, and can request for arbitration before data transfer

FIG. 17 shows an example of the packet format of isochronous transfer.The packet of each channel has a data field, an error correction dataCRC field and a header field. As shown in FIG. 17, the header fieldstores therein a transfer data length, a channel number, various codes,error correction header CRC and the like.

Bus Cycle

In a practical data transfer on the 1394 serial bus, isochronoustransfer and asynchronous transfer can be mixed. FIG. 18 shows a timesequential transition state of mixed isochronous and asynchronoustransfers on the bus. As shown, the isochronous transfer is executedwith a priority over the asynchronous transfer. The reason for this isthat after the cycle start packet, the isochronous transfer can beactivated at a gap length (isochronous gap) shorter than an idle periodgap length (subaction gap) necessary for activating the asynchronoustransfer.

In a general bus cycle shown in FIG. 18, when the cycle #m starts, acycle start packet is transmitted from the cycle master to each node.Each node adjusts time by using this cycle start packet. After apredetermined idle period (isochronous gap), a node which wishesisochronous transfer requests for arbitration in order to transfer apacket.

In the example shown in FIG. 18, packets of channel e, s and k aresequentially and isochronously transferred. This operation fromarbitration request to packet transfer is repeated as many times as thenumber of channels. After all the isochronous transfers during the cycle#m are completed, the asynchronous transfers are executed. When the idletime lapses by the amount of the subaction gap allowing the asynchronoustransfer, the node wishing asynchronous transfer judges that it ispossible to request for arbitration.

The asynchronous transfer is permitted only when the subaction gap foractivating the asynchronous transfer is obtained during the period afterthe completion of asynchronous transfer and before the time (cyclesynch) when the next cycle start packet is transmitted.

In the cycle #m shown in FIG. 18, the isochronous transfers for threechannels and the asynchronous transfers for two packets 1 and 2including ack signals are executed. After the asynchronous packet 2 istransferred, it becomes the time (cycle synch) for the next cycle #(m+1)so that the data transfer during the cycle #m is terminated until thistime.

If it becomes the time (cycle synch) for the next cycle start packetduring an asynchronous or isochronous transfer operation, the transferoperation is not intercepted by all means, but the idle period after thecompletion of this transfer operation is awaited and then the cyclestart packet for the next cycle is transmitted. More specifically, ifone cycle continues longer than 125 μs, the next cycle is shortenedcorrespondingly more than the nominal 125 μs.

Although the period of each cycle can be prolonged or shortened morethan the nominal 125 μs, the isochronous transfer is executed always ateach cycle in order to preserve the real time transfer, whereas theasynchronous transfer is passed if necessary to the next or followingcycle when the cycle time is shortened. Considering also such delayinformation, the cycle master adjusts time at each node.

FIG. 19 is a block diagram showing a portion of the printer 104 andD-VTR 105 in the network configuration shown in FIG. 1. Thecharacteristic features of this invention will be described withreference to FIGS. 19 to 32.

In D-VTR 105 shown in FIG. 19, reference numeral 3 represents a magnetictape, reference numeral 4 represents a recording/reproducing head,reference numeral 5 represents a reproduction processing unit, referencenumeral 6 represents a video decoding unit, reference numeral 7represents a D/A converter, reference numeral 9 represents an outputterminal, reference numeral 10 represents an operation unit, referencenumeral 11 represents a system controller for VTR, reference numeral 12represents a frame memory, reference numeral 13 represents a 1394interface (I/F) unit, and reference numeral 14 represents a selector forselecting specific data from a plurality type of data. In FIG. 19, onlythe reproducing system of D-VTR 105 is shown.

In the printer 104 shown in FIG. 19, reference numeral 17 represents a1394 interface (I/F) unit for the printer, reference numeral 18represents an image processing unit for rasterizing image data so as toprint it at the printer, reference numeral 19 represents a memory forstoring rasterized image data, reference numeral 20 represents a printerhead, reference numeral 21 represents a driver for driving the printerhead 20 and feeding a print sheet, reference numeral 22 represents anoperation unit for the printer, reference numeral 23 represents aprinter controller for controlling the whole operation of the printer104, reference numeral 24 represents a printer information generationunit for generating printer information such as the operation state,resolution, and color/monochrome print performance of the printer 104,and reference numeral 25 represents a data selector.

In D-VTR 105 constructed as above, image data recorded on the magnetictape 3 is read with the recording/reproducing head 4, and thereproduction processing unit 5 converts the read image data into data ofthe reproduction format. Since the read image data was recorded after itwas encoded by a predetermined home use digital video band compressionmethod such as DCT (discrete cosine transform) and VLC (variable lengthcoding), the decoding unit 7 executes a predetermined decoding process.After the image data is converted into analog signals by the D/Aconverter 7, it is output via the external terminal 9 to an externalapparatus.

If desired image data and the like is to be transferred to another nodeby using a 1394 serial bus (1394 cable C), the image data decoded by thedecoding unit 6 is temporarily stored in the frame memory 12, andtransferred via the data selector 14 to the 1394 I/F unit 13 andtransferred via the 1394 cable C, for example, to the printer 104 and PC103. The data selector 14 transfers the image data as well as variouscontrol data from the system controller 11 to the 1394 I/F unit 13. Ifthe transferred image data is data to be directly printed on the printer104, the printer 104 receives the image data via the 1394 I/F unit 17,whereas if the image data is data to be transferred to another node suchas PC 103, the image data is transferred via the 1394 I/F node 17 to theobject node.

A reproduction operation or the like of D-VTR 105 is instructed from theoperation unit 10. In accordance with an instruction entered from theoperation unit 10, the system controller 11 controls the VTRreproduction processing unit and other necessary circuits. Dependingupon an entered instruction, for example, the system controller 11supplies a control command to the printer 104 to transfer image data tothe printer 104 via the data selector 14, 1394 I/F unit 13, and 1394cable C.

Printer data such as printer operation state data supplied from theprinter 104 via the 1394 cable C can be received at the systemcontroller 11 via the 1394 I/F unit 13 and data selector 14. If theprinter data is not necessary for D-VTR 105, it is not supplied to thesystem controller 11 but is transferred to D-VTR 106 via the 1394 I/Funit 13 and 1394 cable C (refer to the connection state shown in FIG.1). The printer data may be transferred to PC 103 via the 1394 I/F unit17 and 1394 cable of the printer 104.

The data selectors 14 and 25 of D-VTR 105 and printer 104 selectinput/output data and discriminately supply the selected data to propercircuit elements.

Next, the operation of the printer 104 will be described. Data input tothe 1394 I/F unit 17 is classified into each data type by the dataselector 25. Data to be printed is supplied to the image processing unit18 whereat it is processed to be converted into data suitable forprinting, and stored as print image data in the memory 19 under thecontrol of the printer controller 23. The printer controller 23 operatesto transfer the print image data read from the memory 19 to the printerhead 20 to print it out. The control of the printer head 20 and thecontrol of paper feed are performed by the driver 21 under the controlof the printer controller 23. That is, the printer controller 23controls the print operation indirectly. The operation unit 22 of theprinter 104 enters instructions for various operations such as paperfeed, reset, ink check, and printer standby/stop. In accordance with anentered instruction, each circuit portion is controlled by the printercontroller 23.

If data input to the 1394 I/F unit 17 is command data for the printer104 issued from PC 103, D-VTR 105 or the like, this command data istransferred via the data selector 25 to the printer controller 23 whichthen controls each circuit portion of the printer. The printerinformation generation unit 24 generates printer information such as aprinter operation state, a message indicating a print end or a printready state, an alarm message indicating paper jamming, operation error,ink presence/absence or the like, and print image information. Thisprinter information can be supplied to another port via the dataselector 25 and 1394 I/F unit 17.

In accordance with the output printer information, PC 103 and D-VTR 105execute a display process and data process matching the printer state. Auser looking at a message and print image information displayed on PC inaccordance with the printer information (also on D-VTR 105 if it has adirect print function), can enter a proper command from PC 103 (alsofrom D-VTR 105) to supply it via the 1394 serial bus to the printer 104so that the operation of each circuit portion of the printer 104 and theoperation of the image processing unit 18 can be controlled by theprinter controller 23.

As above, image data and various types of command data are transferredvia the 1394 serial bus interconnecting PC 103, D-VTR 105 and printer104. The method of transferring data from D-VTR 105 is in conformitywith the previously described 1394 serial bus specifications. Over the1394 serial bus, video data (and audio data) is mainly transferred asIso data by the isochronous transfer method, and command data istransferred as Async data by the asynchronous transfer method.

Some data is more preferably transferred through asynchronous transferthan through isochronous transfer. In such a case, the asynchronoustransfer method is used always. Printer data supplied from the printeris transferred as Async data by the asynchronous transfer method.However, data having a large capacity, such as image data, istransferred as Iso data by the isochronous transfer method.

In the network configured as shown in FIG. 1 by using the 1394 serialbus, data can be bidirectionally transferred from D-VTR 105 and printer104 to PC 103, D-VTR 106, DVD player 107, CD player 108, AV amplifier102 and TV monitor 101 according to the 1394 serial bus specifications.

The TV monitor 101, AV amplifier 102, PC 103, D-VTR 106, DVD player 107,and CD player 108 each have function control units specific to eachapparatus. However, they have the data selector and 1394 I/F unitsimilar to those of D-VTR 105 and printer 104 which are essential fordata communications over the 1394 serial bus so as to properly transferinput/output data to and from each circuit block of the apparatus. Theoutline of IEEE 1394 technologies have been described above.

FIG. 20 is a block diagram of a video camera 2600 having an IEEE 1396serial I/F unit. The video camera 2600 is mainly classified into animage pickup unit, a digital signal processor 2601, and a camera systemcontroller 2602, the image pickup unit being constituted of anunrepresented optical lens unit, an iris stop 2603, a CCD 1604, an AGCcircuit 2605, an A/D converter 2606, an iris stop driver 2607, a CCDdriver 2608, and a timing generator 2609.

Image light focussed on an image pickup plane of CCD 2604 via theoptical lens unit and iris stop 2603 is photoelectrically converted byCCD 2604 into analog image signals. The analog image signal is amplifiedby the AGC circuit 2605 and converted by the A/D converter 2606 into adigital signal which is input to the digital signal processor 2601.

Of the image signal input to the digital signal processor 2601, aluminance component Y is input to a signal processing block 2614 whereatthe level of the luminance component is compared with a reference signalgenerated by an iris stop control reference signal generator 2615. Acomparison result from the signal processing block 2614 is supplied tothe iris stop driver 1607 to automatically control the iris stop 2603 sothat an iris stop value suitable for exposure light can be obtainedalways.

Of the image signal input to the digital signal processor 2601, a colorsignal component is input to a color separation matrix 2610. The colorseparation matrix 2610 separates the color signal into three colorsignal components of R (red), G (green) and B (blue). Of these, the Rand B color signal components are input to level control circuits 2611and 2612 to control the levels thereof. The G color signal component andthe R and B color signal components output from the level controlcircuits 2611 and 2612 are input to a color difference matrix 2613 to beconverted into R-Y and B-Y color difference signals.

Similar to the iris stop value control, for the level control of thecolor signal components, the levels of the R-Y and B-Y color differencesignals output from the color difference matrix 2613 are compared by thesignal processing block 2614 with the reference signals generated by R-Yand B-Y level control reference signal generators 2616 and 2617, and acomparison result is supplied from the signal processing block 2614 tothe level control circuits 2611 and 2612. With this level control forthe color signal components, a proper white balance can be obtainedalways.

A time for accumulating electric charges corresponding to the amount oflight focussed on the image pickup plane of CCD 2604 in each cell of CCD2604, i.e., a shutter speed, is controlled by a CCD drive signalsupplied from the timing generator 2609 to CCD 2604 via the CCD driver2608. The timing generator 2609 is connected to an I/F unit 2625 of thecamera system controller 2602, and controls the CCD accumulation time inaccordance with a control command from a CPU 2626. The output levels ofthe iris stop control reference signal generator 2615 and R-Y and B-Ylevel control reference signal generators 2616 and 2617 are alsocontrolled in accordance with control signals supplied from the camerasystem controller 2602 via IF units 2625 and 1618.

The camera system controller 2602 of the video camera 2600 cancommunicate with an external PC 103 via a 1394 cable C and a 1394 I/Funit 2627. With this communications function, it is possible to controlthe video camera 2600 externally from PC 103. Namely, in accordance withcamera control commands from PC 103, CPU 2626 supplies signals forchanging the levels of signals to be output from the iris stop controlreference signal generator 2615 and R-Y and B-Y level control referencesignal generators 2616 and 1617, to thereby change reference values forthe iris stop value, R-Y and B-Y levels and control the iris stop value,color hue and density from the external.

The reference values of the levels of signals to be output from the irisstop control reference signal generator 2615 and R-Y and B-Y levelcontrol reference signal generators 2616 and 1617, are stored in astandard control data storage area 2621 of a RAM 2629. Usually, data inthis area 2621 is transferred to a control data storage area 2623 of aRAM 2630 and then the control condition data is supplied to the irisstop control reference signal generator 2615, R-Y and B-Y level controlreference signal generators 2616 and 1617, and timing generator 2609, sothat a proper photographing condition can be automatically set.

In controlling the video camera 2600 from PC 103, the camera controlcommands transmitted from PC 103 to the 1394 I/F unit 2627 are changedto data suitable for the video camera 2600 by CPU 2626 and then suppliedto the digital signal processor 2600 via the I/F unit 2625. Data outputfrom the I/F unit 2625 to the digital signal processor 2601 is alsostored in an adjustment control data storage area 2622 of RAM 2629, andread by CPU 2626 via the control data storage area 2623 when necessary.In this manner, camera control information supplied from PC 103 istemporarily stored in the video camera 2600 and read when necessary torepeat similar controls.

CPU 2626 controls an access to RAMs 2629 and 2630 via an addressassignment unit 2620 and an address and R/W assignment unit 2624. Whenthe photographing condition set by PC 103 is set, the data in theadjustment control data storage area 2622 is written in the control datastorage area 2623, whereas when the standard photographing condition isset, the data in the standard control data storage area 2621 is writtenin the control data storage area 2623.

A ROM 2628 is preset with control programs corresponding to the flowcharts shown in FIGS. 7 to 10 and FIG. 13 and the flow chart shown inFIG. 22 to be later described. CPU 2626 executes these control programs.The control programs corresponding to flow charts shown in FIGS. 21, 23,27, 29 and 30 to be executed by PC 103 and image contents, data and thelike shown in FIGS. 24, 25, 26, 28, 31 and 32, respectively to be laterdescribed may be stored in an unrepresented storage medium such as afloppy disk, a hard disk and a CD-ROM and supplied to PC 103.

When a 1394 cable C is connected, the video camera 2600 and PC 103 judgewhether a mode setting operation is to be performed or not.Specifically, on the PC 103 side, as shown in FIG. 21, when a routinestarts at Step S501, it is checked at Step S502 whether a 1394 cable Cis connected. This check is performed by detecting an occurrence of abus reset.

If a bus reset does not occur, the routine stands by without performingany operation, whereas if there is an occurrence of a bus reset, it isjudged at Step S503 whether the video camera 2600 is connected to the1394 cable C. This judgement whether the video camera 2600 is connectedor not, is performed for example by checking the 64-bit address readfrom the address space of the 1394 serial bus of the video camera 2600.

If it is judged at Step S503 that the video camera 2600 to be controlledis not connected, the routine returns to Step S502. If it is judged thatthe video camera 2600 to be controlled is connected, it is judged atStep S504 whether the video camera 2600 is ready for reception of a modesetting command from PC 103. This ready state for reception of the modesetting command corresponds to a manual setting mode or the like, asdifferent from a tape reproduction mode of the video camera 2600, i.e.,a camera mode, and other various auto modes.

If not in the ready state for reception of the mode setting command, theroutine returns to Step S503 whereas it is checked whether the videocamera 2600 to be controlled is still connected, to thereafter followStep S504. If it is judged at Step S504 that the video camera 2600 isready for reception of the mode setting command, a mode setting programis activated and a mode setting command is supplied from PC 103 toremotely control the video camera 2600.

On the video camera 2600 side, as shown in the flow chart of FIG. 22,when a routine starts at Step S506, an ordinary camera operation startsat Step S507. The ordinary camera operation is performed under theconditions that the standard control data in the standard control datastorage area 2621 is written in the control data storage area 2623 shownin FIG. 20.

While the ordinary camera operation is performed, CPU 2626 alwaysmonitors at Step S508 whether a 1394 cable C is connected. As a methodof detecting a connection of the 1394 cable C, for example, a change inthe bias voltage at the port is detected. If it is not judged at StepS508 that a 1394 cable C was connected, the routine returns to StepS507, whereas if it is judged that a 1394 cable C was connected, at StepS509 the routine stands by until the bus reset is completed, and at StepS510 it is checked whether the connection partner is PC 103. This checkis performed for example by checking the 64-bit address read from theaddress space of the 1394 serial bus of the video camera, similar tothat described with the PC 103 side operation.

If the connection partner is PC 103, it is checked at Step S511 whetherthe PC 103 side operates the mode setting program. This check isperformed for example by reading information of the application layershown in FIG. 3 or confirming Async data transferred between PC 103 andvideo camera. If it is confirmed at Step S512 that the PC 103 sideoperates the mode setting program, the routine advances to Step S512whereat the control reference value and shutter speed are changed andthe contents in the control data storage area 2623 are rewritten inaccordance with the command from PC 103, to thereby perform the modesetting operation of the video camera 2600.

The video camera 2600 side judges whether the mode setting operation isexecuted in accordance with a command from PC 103, while the videocamera 2600 sequentially executes each of judgement Steps S508 to S511.If any one of the judgement Steps is not satisfied, the ordinary cameraoperation continues to be executed without following the command from PC103.

When the video camera 2600 executes the mode setting operation inaccordance with the command from PC 103, it is necessary for PC 103 toexecute the mode setting program as described above. FIG. 23 is a flowchart illustrating the outline of a mode setting program (correspondingto Step S505 in FIG. 21) to be executed by PC 103.

First, at Step S5051 the type of a setting mode selected upon operationof an unrepresented mouse or keyboard is judged. In accordance with theselected setting mode, a program corresponding to one of a photographiccondition setting mode at Step S5052, a standard setting mode at StepS5053 and a photographing image confirmation and condition setting modeat Step S5054 is executed.

The details of the photographic condition setting mode at Step S5052,standard setting mode at Step S5053 and photographing image confirmationand condition setting mode at Step S5054 will be given in this order.

Standard Setting Mode

In the standard setting mode, the contents of various photographingconditions for the video camera 2600 are stored in advance in PC 103,and when a typical photographing condition is selected by PC 103, thevideo camera 2600 is set so as to match the selected photographingcondition by PC 103.

When the standard setting mode is selected, a screen 601 shown in FIG.24 is displayed on the monitor of PC 103. Several photographing scenesare displayed on the screen 601 which are difficult to be taken with agood image quality by using general automatic setting of the videocamera 2600. If an evening sun photographing mode is selected with amouse or the like, a display is changed to a screen 602 shown in FIG.25. Displayed on this screen 602 are an example 603 of a photographedimage of an evening sun, an explanation 604 of the evening sunphotographing mode, a mode setting conformation message 605, and acamera setting button 606.

It is usual that setting sun is to be photographed reddish. However,with general automatic setting of the video camera 2600, the auto whitebalance function operates to suppress red color components and makewhitish as much as possible. Therefore, a photographed image is lessreddish and a good image like an evening sun cannot be photographed.

When the evening sun photographing mode is selected in the standardsetting mode, for example, the levels of signals to be output from theR-Y and B-Y level control reference signal generators 2616 and 2617shown in FIG. 20 are changed to the values preset in PC 103, so that animage emphasizing red is output from the video camera 2600. At the sametime, in order not to make CCD 2600 saturated, a proper preset shutterspeed and iris stop value are supplied from PC 103 to the video cameraso that an evening sun can be taken more clearly. When an operator of PC103 clicks the camera setting button 606 shown in FIG. 25, theabove-described preset values are transferred from PC 103 to the videocamera 2600 which in turn sets its values in accordance with thesupplied preset values and stores the supplied preset values.

In the above description, although the white balance, shutter speed andiris stop value are used as the camera setting conditions for theevening sun photographing mode, other parameters such as thoseenumerated in FIG. 26 may be supplied from PC 103. For example, in awedding reception photographing mode (refer to FIG. 24), in order toprevent the faces of a bride and bridegroom from becoming whitish, PC103 controls the iris stop 2603 to be stopped down more or less.

In a living thing observation (closeup) mode (refer to FIG. 24), PC 103can control to shorten a focal length and provide an optical conditionallowing macro photographing. In a ski ground mode (refer to FIG. 24),in order to avoid light diffraction to be caused by an excessive stopdown of the iris stop 2603 under high illuminance, PC 103 can control tosuppress the iris stop amount to a predetermined value and set a highshutter speed. In a night view photographing mode (refer to FIG. 24), inorder to photograph a good color of neon lights, PC 103 can control toset proper values of the iris stop, shutter speed and white balance.

Photographing Condition Setting Mode

FIG. 27 is a flow chart illustrating the process of the photographingcondition setting mode (Step S5052 in FIG. 23) to be executed by PC 103.As the process of the photographing condition setting mode starts, amode selection screen similar to that shown in FIG. 24 is displayed onthe monitor of PC 103, and an operator selects a desired scene. PC 103stands by until the operator selects a mode of a desired photographingscene (Step S521). After the scene mode is selected, the standard camerasetting condition of the selected scene mode is read from the memory ofPC 103. Assuming that the operator selects the evening sun photographingmode, the standard camera setting condition read at Step S522 is thesame as that selected in the standard setting mode described previously.

Next, at Step S523 a screen 2401 shown in FIG. 28 is displayed on themonitor of PC 103. Displayed on this screen 2401 shown in FIG. 28 are amode explanation 2402, an example 2409 of a photographed evening sun, ahue adjustment tab 2403, a color density tab 2404, an iris stop valueadjustment tab and iris stop value display 2405, a shutter speedadjustment tab and shutter speed display 2406, a next operationexplanation 2407, and a camera setting button 2408.

In the photographing condition setting process at Step S524, theoperator moves each adjustment tab with a mouse or the like to changethe standard setting state of the video camera 2600 in accordance with apersonal preference. FIG. 29 is a flow chart illustrating the details ofthe photographing setting process at Step S524 shown in FIG. 27.

As the process starts at Step S524 shown in FIG. 27, it is checked atStep S5241 shown in FIG. 29 which item the operator intends to change.More specifically, since each tab displayed at the cursor position ofthe mouse is operated upon, a coincidence between the cursor position ofthe mouse and the display position of each tab is detected. For example,if the mouse cursor on the hue adjustment tab 2403 is moved to the leftwhile the right button of the mouse is clicked, the setting contents arechanged at Step S5242 to emphasize red color, and at the same time thetab display is moved to the left as the mouse cursor moves.

Similar adjustment and setting contents change are performed at StepsS5243, S5244 and S5245 respectively for color density, iris stop valueand shutter speed. It is checked at Step S5246 whether the camerasetting button 2408 shown in FIG. 28 is clicked. If not, the routinereturns to Step S5241 to accept the next adjustment. If the camerasetting button 2408 is clicked, this routine is terminated.

As a series of adjustment operations is performed, the hue, colordensity, screen brightness and the like of the photographed example 2409on the screen 2401 shown in FIG. 28 may be changed with a position ofeach tab to show an image to the operator. In this case, the operatorcan set the photographing conditions more conveniently and easily.

After the photographing conditions are set in the manner describedabove, the camera setting conditions are rewritten in PC 103 at StepS525 shown in FIG. 27. Next, at Step S526 PC 103 transfers theabove-described various setting values to the video camera 2600 whichrewrites the camera setting conditions on the video camera 2600 side. PC103 checks at Step S527 whether the setting process on the video camera2600 side is completed. If not, the routine returns to Step S526,whereas if completed, the routine is terminated.

As above, since the operator can adjust and change the standard settingof each photographing mode, the setting state of the video camera 2600matching the operator's preference can be remotely supplied from PC 103.

Photographing Image Confirmation and Condition Setting Mode

FIG. 30 is a flow chart illustrating the details of the process of thephotographing image confirmation and condition setting mode at StepS5054 shown in FIG. 23. As the process of the photographing imageconfirmation and condition setting mode starts, a screen similar to thatshown in FIG. 24 is displayed on the monitor of PC 103. The operatorselects a desired photographing scene. PC 103 stands by at Step S541until the operator selects the photographing scene. After the scene modeis selected, at Step S542 the standard camera setting condition of theselected scene mode is read from the memory of PC 103. Assuming that theoperator selects the evening sun photographing mode, the standard camerasetting condition read at Step S542 is the same as that selected in thestandard setting mode described previously.

Next, at Step S543 a screen 2501 shown in FIG. 31 is displayed on themonitor of PC 103. Displayed on this screen 2501 shown in FIG. 31 are amode explanation 2502, an image loading display 2504, a next operationexplanation 2503, and a camera image loading button 2505. In accordancewith the display on the screen 2501, the operator searches and selects aproper sample image of a photographed evening sun, while reproducing atape (not shown) of the video camera 2600. The searched and selectedsample image is loaded in PC 103 at Step S544 when the camera loadingbutton 2505 is clicked. Since it takes some time to load the reproducedimage from the video camera, whether the image loading is completed ismonitored at Step S545. If completed, the screen 2506 shown in FIG. 32is displayed at Step S546.

Displayed on this screen 2506 are a mode explanation 2502, an image(i.e., an actually photographed evening sun image) 2507 loaded at StepS544, a hue adjustment tab 2403, a color density tab 2404, an iris stopvalue adjustment tab and iris stop value display 2405, a shutter speedadjustment tab and shutter speed display 2406, a next operationexplanation 2407, and a camera setting button 2408.

In the photographing condition setting process at Step S547, theoperator moves each adjustment tab with a mouse or the like to changethe standard setting state of the video camera 2600 in accordance with apersonal preference.

As a series of adjustment operations is performed, the hue, colordensity, screen brightness and the like of the photographed example 2409on the screen 2401 shown in FIG. 28 may be changed with a position ofeach tab to show an image to the operator. In this case, the operatorcan set the photographing conditions more conveniently and easily.

After the photographing conditions are set in the manner describedabove, the camera setting conditions are rewritten in PC 103 at StepS548. This process becomes necessary when an image is again photographedunder the photographing condition set at Step S547 and thisphotographing condition is desired to be changed again.

Next, at Step S549 PC 103 transfers the above-described various settingvalues to the video camera 2600 which rewrites the camera settingconditions on the video camera 2600 side. PC 103 checks at Step S550whether the setting process on the video camera 2600 side is completed.If not, the routine returns to Step S549, whereas if completed, theroutine is terminated.

As above, since the operator can adjust and change the standard settingof each photographing mode, by confirming the actually photographedimage, the setting state of the video camera 2600 matching theoperator's preference can be remotely supplied from PC 103.

As described above, according to the embodiment, the control contentsheretofore fixedly set in a video camera can be changed remotely from PC103. Since various camera control conditions for various subjects arestored in PC 103 without storing a large amount of control informationin a video camera, PC 103 can set the video camera control conditionmatching a subject to be photographed. An operator of PC 103 can adjustthe video camera control condition preset in PC 103 to provide the videocamera control condition matching the operator's preference. If theactually photographed image is loaded in PC 103 when the operatoradjusts the video camera control condition, an image to be photographedafter adjustment can be simulated beforehand on PC 103.

Modification

The invention is not limited only to the above embodiment. For example,control data such as an iris stop value, shutter speed and white balancestored in PC for a specific photographing condition such as a nightscene may be automatically transmitted to a video camera when aconnection to the video camera is detected. The invention is alsoapplicable to a video camera for photographing still images in additionto a video camera for photographing moving images.

If an image pickup apparatus and a printer are connected by a 1394cable, a photographed image (reproduced image) having a definitioncorresponding to the printer performance (such as a resolution, printspeed and full color/mono color) may be automatically transmitted to theprinter by detecting the printer performance, or the photographed imagemay be automatically transmitted at a transmission speed matching theprinter performance to print it out. In this case, information of theprinter performance read from the printer information generation unit 24may be positively transmitted from the printer to the image pickupapparatus or it may be transmitted from the printer in response to aninquiry from the image pickup apparatus.

As described so far, according to the invention, an image pickup controlapparatus for controlling an image pickup apparatus via a datacommunications interface unit, comprises: storage means for storingcontrol data for controlling the image pickup apparatus; connectiondetecting means for detecting a connection to the image pickup apparatusvia the data communications interface unit; and transmission controlmeans for transmitting the control data stored in the storage means tothe image pickup apparatus when the connection detecting means detects aconnection to the image pickup apparatus. Accordingly, the image pickupapparatus can be remotely and reliably controlled from anotherapparatus.

Many widely different embodiments of the present invention may beconstructed without departing from the spirit and scope of the presentinvention. It should be understood that the present invention is notlimited to the specific embodiments described in the specification,except as defined in the appended claims.

1. An image pickup control apparatus for controlling an image pickupapparatus via a data communications interface unit, the image pickupcontrol apparatus comprising: a connection detecting unit which detectsa connection to the image pickup apparatus via the data communicationsinterface unit; a storage unit which stores a plurality of kinds ofcontrol data for controlling the image pickup apparatus in accordancewith a plurality of photographing conditions, the names of thephotographing conditions, example photographed images, different fromimages photographed by the user using the image pickup apparatus andrepresenting different kinds of scenes a user of the image pickupapparatus will use the image pickup apparatus to photograph that areassociated with particular photographing conditions associated withparticular values for the control data and that are to be displayedbefore performing photographing of a specific scene with the imagepickup apparatus, and description information for explaining a scene tobe photographed in each of the plurality of photographing conditions,that is different from the control data associated with each of thephotographing conditions; a setting unit which displays the plurality ofphotographing conditions, which, prior to photographing by the imagepickup apparatus, selects a desired photographing condition from amongthe plurality of displayed photographing conditions to display theplurality of kinds of control data associated with the selectedphotographing condition, the name of the selected photographingcondition, the example photographed image associated with the selectedphotographing condition, which is different from an image photographedby the user using the image pickup apparatus and which represents thekind of scene a user of the image pickup apparatus will use the imagepickup apparatus to photograph after the example photographed image isdisplayed, and the description information for explaining the scene tobe photographed in the selected photographing condition, that isdifferent from the control data associated with the selectedphotographing condition, and changes the plurality of kinds of controldata corresponding to the selected photographing condition; and acontrol unit which is communicatively coupled to said connectiondetecting unit and said setting unit, wherein in a case that saidconnection detection unit detects the connection to the image pickupapparatus, said control unit effects control so as to transmit to theimage pickup apparatus the plurality of kinds of control data changed bysaid setting unit.
 2. An image pickup apparatus comprising: a controlunit which sets photographing control conditions of said image pickupapparatus in accordance with each of a plurality of photographing modes;a storage unit which stores the plurality of photographing modes,example photographed images, different from images photographed by theuser using the image pickup apparatus and representing different kindsof scenes a user of the image pickup apparatus will use the image pickupapparatus to photograph that are associated with particularphotographing modes and particular photographing conditions associatedwith particular values for control data and that are to be displayedbefore performing photographing of a specific scene with the imagepickup apparatus, and description information for explaining a scene tobe photographed in each of the plurality of photographing modes, that isdifferent from the photographing control condition associated with eachof the plurality of photographing modes; a selection unit which selectsany one of the plurality of photographing modes; and a display unitwhich displays the example photographed image associated with theselected photographing mode, which is different from an imagephotographed by the user using the image pickup apparatus and whichrepresents the kind of scene a user of the image pickup apparatus willuse the image pickup apparatus to photograph after the examplephotographed image is displayed, and description information,corresponding to the one of the plurality of photographing modes,selected by said selection unit, wherein said control unit sets controlconditions corresponding to the photographing mode selected by saidselection unit, as the photographing control conditions of said imagepickup apparatus.
 3. An image pickup apparatus according to claim 2,wherein said display unit displays simultaneously an example ofphotographed image and the description information.
 4. An image pickupapparatus according to claim 2, wherein the description informationincludes an explanation of the example of photographed images.
 5. Animage pickup apparatus according to claim 2, wherein said image pickupapparatus includes a camera and a computer equipment connected to saidcamera so that said camera and said computer equipment are able tocommunicate with each other.
 6. A control method of an image pickupapparatus which can set photographing control conditions in accordancewith each of a plurality of photographing modes, said control methodcomprising: a selection step of selecting any one of the plurality ofthe photographing modes stored in a storage unit which stores examplephotographed images associated with the selected photographingconditions and the plurality of photographing modes, which are differentfrom an image photographed by the user using the image pickup apparatusand which represent the kind of scene a user of the image pickupapparatus will use the image pickup apparatus to photograph after theexample photographed image is displayed, and description information forexplaining a scene to be photographed in each of the plurality ofphotographing modes, that is different from a photographing controlcondition associated with each of the plurality of photographing modes;a display step of displaying, on a display unit, the example ofphotographed image associated with the selected photographing mode,which is different from an image photographed by the user using theimage pickup apparatus and which represents the kind of scene a user ofthe image pickup apparatus will use the image pickup apparatus tophotograph after the example photographed image is displayed, and thedescription information for explaining a scene to be photographed in thephotographing mode selected in said selecting step, that is differentfrom the photographing control condition associated with each of theplurality of photographing modes; a control step of setting controlconditions corresponding to the photographed mode selected in saidselection step, as the photographing control conditions of the imagepickup apparatus.
 7. A control method of the image pickup apparatusaccording to claim 6, wherein said display step displays simultaneouslythe example photographed image and the description information.
 8. Acontrol method of the image pickup apparatus according to claim 6,wherein the description information includes an explanation of theexample of the photographed image.
 9. A program for causing a computerof an image pickup apparatus to execute the control method of the imagepickup apparatus set out in claim 6.